Why Is the Verticality of Andean Topography Important in Determining

Why is the verticality of Andean topography important in determining the nature of cultures there?

A) Because most of the upper areas of the Andean region were uninhabitable, it was necessary for people to control the lower elevations.
B) Because the Andean region is divided into microecologies vertically, it became important for people to control as many different vertical ecological zones as possible.
C) Because of the aridity of the lower valleys, people struggled to control the upper zones to establish sedentary agriculture.
D) Because of the absence of domesticated animals in the Andean region, it was necessary to control those ecological zones suitable for agriculture.